code: def test_getitem_preserves_freq(self, simple_index):
      index = simple_index
      assert index.freq is not None
  
      result = index[:]
      assert result.freq == index.freq
  
file_path: pandas/pandas/tests/indexes/test_datetimelike.py
imports: import numpy
  import pytest
  import pandas
  import pandas._testing
label_desc: Use image node_id 11 for calling the TestDatetimeLike obj's underlying member method code with example usage: obj.test_getitem_preserves_freq(simple_index) without return types